The invention pertains to semiconductor processing, and in particular to a method and system providing a high flux of point of use activated reactive species for semiconductor processing.
Reactive species are employed in a number of important steps in the processing of semiconductor substrates. For example, reactive species may be employed for removing, or ashing the photoresist, and for etching of siliconiferous, metallic, or ceramic materials. It is known in the prior art to use a laser beam to selectively induce dissociation of a gaseous component to produce the desired gaseous reactive species for such semiconductor processing. Examples of such semiconductor processing systems are disclosed by the following references, which may be relevant to various aspects of the present invention.
U.S. Pat. No. 4,260,649 discloses providing a workpiece in a gaseous environment and a laser beam in close proximity and parallel to the surface of the workpieces in order to produce a gaseous reactant product for reaction with a surface of the workpiece.
U.S. Pat. No. 5,814,156 discloses providing a gaseous reactant in the vicinity of foreign material found on a surface of a substrate to form a non-solid by-product by delivering laser energy to the surface of the substrate to aid the gaseous reactant to react with the foreign material to form the non-solid by-product. The laser energy is arranged to be insufficient to damage the surface of the substrate.
Although the above-mentioned processing systems have been suitable for their intended purposes, one problem with these prior art systems is that they do not provide maximum laser beam energy at the point of use. Since activated gaseous reactive species have very short lifetime, it is therefore highly desirable to provide maximum laser beam energy at the point of use so that a high flux of activated reactive species is generated proximate to the surface of a workpiece.